The standard treatment for gastrointestinal cancer is surgical resection and perioperative adjuvant treatment. Multidisciplinary treatment for gastrointestinal cancer leads to body composition changes. Body composition changes, such as skeletal muscle loss and body weight loss, during multidisciplinary treatment result in poor physical activity, severe toxicity of chemotherapy and/or radiation therapy, and poor oncological outcomes. Therefore, the hypothesis is that minimization of body composition changes during multidisciplinary treatment in gastrointestinal cancer patients, the continuation of postoperative adjuvant treatment in these patients might improve, thereby improving the oncological outcomes. Given this hypothesis, recent studies have focused on introducing perioperative oral nutritional treatment for gastrointestinal cancer patients. Thus far, oral nutritional treatment has proven promising and showed some clinical benefits for gastrointestinal cancer patients during the perioperative period. However, whether or not oral nutritional treatment has clinical benefits on the long-term oncological outcomes in gastrointestinal cancer remains unclear. To optimize oral nutritional treatment for gastrointestinal cancer patients, it is necessary to clarify the benefits of oral nutritional treatment on the long-term oncological outcomes in gastric cancer patients and establish the optimal approach to oral nutritional treatment.
Keywords: Oral nutritional treatment; esophageal cancer; gastric cancer; review.